The present invention relates to ball joints in general, and more specifically, to a ball joint with a base mount having lubrication means therebetween.
Previously, many different types of ball joints have been used to provide an effective means for transferring energy while simultaneously permitting pivoting of the joint. Conventional ball joints have been in use for many decades, primarily in automotive and large over-the-road equipment, but also in smaller applications where limited movement is required in an angular axis. Lubrication of ball joints has been accomplished using a variety of methods including grease, oil, resilient low-friction substances and the like.
Lieber, et al in U.S. Pat. No. 5,672,023 teaches a ball joint with a socket and a shell that supports the ball. A spring element supporting an underside of a cover that closes the ball joint socket and provides a constant resilient force upon the ball to compensate for the wear-related elasticity of the ball until a defined wear is reached after assembly. The spring element is supported in the center of the cover by spring tabs that point toward the center and transform into a cylindrical center part in the shape of a ball race.
U.S. Pat. No. 5,509,478 of Idosako, et al is for a ball joint that compensates for manufacturing tolerances of the components, and functions under large loads. A rigid bearing seat has an elastic restoring force that compensates for tolerances under variable loads. The housing and seat permit incremental increases in areas, thereby tolerating larger loads without deformation of the bearing seat.
U.S. Pat. No. 5,069,433 issued to Womack discloses a swivel ball mounted in a clampable base having a pair of split socket members that are forced together by the jaws of a vice.
Bryant in U.S. Pat. No. 4,617,430 teaches a swivel mounting base with a locking screw that permits locking a mounting surface in a desired position relative to the base. The mounting surface is adapted to permit attachment of a device on the dash board of a vehicle.
U.S. Pat. No. 4,256,413 issued to Abe is for a ball joint mounted in one or two structural members that are joined together by the ball. The mounting structure is self-chalking by means of a hollow cylindrical housing of the ball joint and a cylindrical portion of one of the structural members. As the housing is press fitted into the cylindrical portion of at least one of the members, the member plastically deforms to firmly secure the ball in a single member.
Manita, et al disclose in U.S. Pat. No. 4,034,996 a ball joint used in a torque rod of an automobile. No lubrication is required as the ball is mounted into brackets that are utilized in conjunction with a bearing ring made of a synthetic resin. The resin is sufficiently resilient to support a shaft that includes a balls on the ends. Oil containing fabrics are provided on both sides of the bearing ring adhering into the periphery of the ball.
U.S. Pat. No. 3,850,443 issued to Hassan is for a ball joint suspension apparatus that has an upper and lower control arm connected by ball joints to a steering knuckle. One ball joint has a stud with a ball on one end mounted within a socket. A pressure plate is backed by a separate washer which is biased by a resilient member. The plate engages the ball and maintains contact with the socket for wear. A retainer is located in the socket, thereby limiting the amount of movement of the separate washer.
In the past ball joints have been used in a multitude of applications, however in most cases the joint is rather fragile and sometimes delicate as their use has been in areas where ultimate strength has not been the governing factor. Therefore, the primary object of the invention is directed to a machined two-piece movable joint with a solid metallic ball that is rugged and durable. This construction utilizes two separate pieces formed as a socket case and a cap, each machined from a solid block of steel and screwed together with the ball captivated therein. This type of construction provides a movable joint that is extremely strong and able to withstand a considerable weight load, even when subjected to external shock and vibration, thus overcoming the difficulties of the prior art.
An important object of the invention is the method of lubrication which makes use of grooves in both the ball and socket and a conventional grease fitting that provides a direct passageway to a diminutive region between the ball and socket. This design utilizes a well known process using conventional grease pumping equipment.
Another object of the invention is the ease of attachment to the item used with the ball joint. For heavy duty use welding is preferred, thereby permitting the socket case to be relatively small. The socket case may also be machined from a rectangular or square block of material and have holes for attachment with conventional bolts. If the application requires a larger footprint, a plate may be easily welded onto the bottom of the case. In automotive applications using hydraulic cylinders, the case may be welded directly to an axle for a simple yet rugged interface.
Still another object of the invention is the ease in which the ball may be removed for replacement or refurbishment. The case, being made in two pieces, is easily dissembled by screwing the cap off and lifting the ball from the socket. The ball is also easily removed as it is attached with threads to the shaft or cylinder.
Yet another object of the invention is its universal usage. While its primary function is directed to automotive hydraulic suspension systems or so-called xe2x80x9clow-riderxe2x80x9d systems, where the ball joint is welded to the axle of a car and the ball is attached to a hydraulic cylinder, a multitude of other applications are equally well-suited to its function. For example, load leveling may be accomplished in uneven terrain using a mounting pad welded to the case and the ball joint attached to the outriggers of a large capacity crane or similar vehicle requiring extended mounting feet under heavy weight loading. Floating tables, such as portable stages, platforms, bleachers and the like require some type of pivot joint to achieve the necessary leveling, therefore the invention fills this need where a robust joint is required. Large machine tools such as lathes, milling machines, punch presses, brakes, etc. may also require joints for leveling on uneven concrete floors. Other uses include motion control tables, such as these employed in flight simulators where hydraulic cylinders continuously change orientation and considerable weight is involved. It may also be noted that any appliance requiring extremely strong pivot joints is easily included in the utility of the invention.
These and other objects and advantage of the present invention will become apparent form the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.